My understanding is you cannot be assigned to an overseas base if you don't agree to it.
I believe most new hires currently are being assigned to MEM.
LAX is a senior base, very senior.
CGN takes a few people each bid, as people "time out", i.e. have to go home due to limitations about how long they can stay there.
Bids have always been once or twice a year.
So....
If you get an interview, ask this question.
If you get a call for a class date, let them know you are interested in CGN.
It can't hurt to make your desires know.
CGN is only the 757 at this time.